java.lang.Object
- org.springframework.http.codec.LoggingCodecSupport
- - org.springframework.http.codec.multipart.MultipartHttpMessageWriter

All Implemented Interfaces:
HttpMessageWriter<MultiValueMap<String,?>>
```
public class MultipartHttpMessageWriter
extends LoggingCodecSupport
implements HttpMessageWriter<MultiValueMap<String,?>>
```
HttpMessageWriter for writing a MultiValueMap<String, ?> as multipart form data, i.e. "multipart/form-data", to the body of a request.
The serialization of individual parts is delegated to other writers. By default only String and Resource parts are supported but you can configure others through a constructor argument.
This writer can be configured with a FormHttpMessageWriter to delegate to. It is the preferred way of supporting both form data and multipart data (as opposed to registering each writer separately) so that when the MediaType is not specified and generics are not present on the target element type, we can inspect the values in the actual map and decide whether to write plain form data (String values only) or otherwise.
Since:
5.0
Author:
Sebastien Deleuze, Rossen Stoyanchev
See Also:
FormHttpMessageWriter

Field Summary
Fields
Modifier and Type Field Description
static Charset DEFAULT_CHARSET
THe default charset used by the writer.
- Fields inherited from class org.springframework.http.codec.LoggingCodecSupport
  logger

Constructor Summary

Constructors
Constructor	Description
`MultipartHttpMessageWriter()`	Constructor with a default list of part writers (String and Resource).
`MultipartHttpMessageWriter(List<HttpMessageWriter<?>> partWriters)`	Constructor with explicit list of writers for serializing parts.
`MultipartHttpMessageWriter(List<HttpMessageWriter<?>> partWriters, HttpMessageWriter<MultiValueMap<String,String>> formWriter)`	Constructor with explicit list of writers for serializing parts and a writer for plain form data to fall back when no media type is specified and the actual map consists of String values only.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`canWrite(ResolvableType elementType, MediaType mediaType)`	Whether the given object type is supported by this writer.
`protected byte[]`	`generateMultipartBoundary()`	Generate a multipart boundary.
`Charset`	`getCharset()`	Return the configured charset for part headers.
`HttpMessageWriter<MultiValueMap<String,String>>`	`getFormWriter()`	Return the configured form writer.
`List<HttpMessageWriter<?>>`	`getPartWriters()`	Return the configured part writers.
`List<MediaType>`	`getWritableMediaTypes()`	Return the `MediaType`'s that this writer supports.
`void`	`setCharset(Charset charset)`	Set the character set to use for part headers such as "Content-Disposition" (and its filename parameter).
`reactor.core.publisher.Mono<Void>`	`write(org.reactivestreams.Publisher<? extends MultiValueMap<String,?>> inputStream, ResolvableType elementType, MediaType mediaType, ReactiveHttpOutputMessage outputMessage, Map<String,Object> hints)`	Write an given stream of object to the output message.

Methods inherited from class org.springframework.http.codec.LoggingCodecSupport
isEnableLoggingRequestDetails, setEnableLoggingRequestDetails

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.springframework.http.codec.HttpMessageWriter
write

- Field Detail
  - DEFAULT_CHARSET
```
public static final Charset DEFAULT_CHARSET
```
    THe default charset used by the writer.
- Constructor Detail
  - MultipartHttpMessageWriter
```
public MultipartHttpMessageWriter()
```
    Constructor with a default list of part writers (String and Resource).
  - MultipartHttpMessageWriter
```
public MultipartHttpMessageWriter(List<HttpMessageWriter<?>> partWriters)
```
    Constructor with explicit list of writers for serializing parts.
  - MultipartHttpMessageWriter
```
public MultipartHttpMessageWriter(List<HttpMessageWriter<?>> partWriters,
                                  @Nullable
                                  HttpMessageWriter<MultiValueMap<String,String>> formWriter)
```
    Constructor with explicit list of writers for serializing parts and a writer for plain form data to fall back when no media type is specified and the actual map consists of String values only.
    Parameters:
    partWriters - the writers for serializing parts
    formWriter - the fallback writer for form data, null by default
- Method Detail
  - getPartWriters
```
public List<HttpMessageWriter<?>> getPartWriters()
```
    Return the configured part writers.
    Since:
    5.0.7
  - getFormWriter
```
@Nullable
public HttpMessageWriter<MultiValueMap<String,String>> getFormWriter()
```
    Return the configured form writer.
    Since:
    5.1.13
  - setCharset
```
public void setCharset(Charset charset)
```
    Set the character set to use for part headers such as "Content-Disposition" (and its filename parameter).
    By default this is set to "UTF-8".
  - getCharset
```
public Charset getCharset()
```
    Return the configured charset for part headers.
  - getWritableMediaTypes
```
public List<MediaType> getWritableMediaTypes()
```
    Description copied from interface: HttpMessageWriter
    Return the MediaType's that this writer supports.
    Specified by:
    getWritableMediaTypes in interface HttpMessageWriter<MultiValueMap<String,?>>
  - canWrite
```
public boolean canWrite(ResolvableType elementType,
                        @Nullable
                        MediaType mediaType)
```
    Description copied from interface: HttpMessageWriter
    Whether the given object type is supported by this writer.
    Specified by:
    canWrite in interface HttpMessageWriter<MultiValueMap<String,?>>
    Parameters:
    elementType - the type of object to check
    mediaType - the media type for the write (possibly null)
    Returns:
    true if writable, false otherwise
  - write
```
public reactor.core.publisher.Mono<Void> write(org.reactivestreams.Publisher<? extends MultiValueMap<String,?>> inputStream,
                                               ResolvableType elementType,
                                               @Nullable
                                               MediaType mediaType,
                                               ReactiveHttpOutputMessage outputMessage,
                                               Map<String,Object> hints)
```
    Description copied from interface: HttpMessageWriter
    Write an given stream of object to the output message.
    Specified by:
    write in interface HttpMessageWriter<MultiValueMap<String,?>>
    Parameters:
    inputStream - the objects to write
    elementType - the type of objects in the stream which must have been previously checked via HttpMessageWriter.canWrite(ResolvableType, MediaType)
    mediaType - the content type for the write (possibly null to indicate that the default content type of the writer must be used)
    outputMessage - the message to write to
    hints - additional information about how to encode and write
    Returns:
    indicates completion or error
  - generateMultipartBoundary
```
protected byte[] generateMultipartBoundary()
```
    Generate a multipart boundary.
    By default delegates to MimeTypeUtils.generateMultipartBoundary().

Class MultipartHttpMessageWriter

Field Summary

Fields inherited from class org.springframework.http.codec.LoggingCodecSupport

Constructor Summary

Method Summary

Methods inherited from class org.springframework.http.codec.LoggingCodecSupport

Methods inherited from class java.lang.Object

Methods inherited from interface org.springframework.http.codec.HttpMessageWriter

Field Detail

DEFAULT_CHARSET

Constructor Detail

MultipartHttpMessageWriter

MultipartHttpMessageWriter

MultipartHttpMessageWriter

Method Detail

getPartWriters

getFormWriter

setCharset

getCharset

getWritableMediaTypes

canWrite

write

generateMultipartBoundary